Removal and Installation
PART-SVN234B-EN
25
ii. Use 40% silver brazing alloy with flux.
iii. Start heating the tube first. Evenly heat the tube,
location 1 (see
), until it reaches a dull
red color. When using flux, this color is also a
good indicator of when the proper brazing
temperature has been reached. Continue
heating the tube until the flux passes the
“bubbling” temperature range and becomes
quiet, completely fluid, and transparent—it
should have the appearance of clear water.
iv. Direct the flame from the tube to the fitting,
evenly heating it until the flux that may be
remaining in the fitting is also completely fluid.
v. Sweep the torch between the fitting and the
tube, locations 1 and 2 (see
), with
most of the heat being applied to the heavier and
slower-heating fitting until the tube and fitting
reach and maintain a uniform heat in both parts.
Figure 19. Brazing locations 1 and 2
vi. Pull the flame slightly back and feed the brazing
material in between the fitting and the tube. If
the joint has been properly heated, the braze
material should flow around and into the joint.
Important:
The heated base metal should melt the
filler; the heat from the torch flame should
not be what melts the filler.
vii.Once the braze material has flowed around and
into the joint, briefly move the torch around the
fitting to ensure complete capillary action into
the joint.
viii.Check the joint to visually ensure that the braze
material is completely around the joint.
e. Post-Braze
NOTICE
NOTICE
Clean Flux From Joint!
Flux is corrosive and could lead to long-term problems
and equipment damage if not properly removed.
Quench the joint with water or a wet rag while the joint
is still hot—but below 900°F—to shock off the flux. If
not cleaned off, flux could hide leaks.
•
Tandem (two compressors) and trio combinations
(three compressors) with uneven compressor
combinations requires the use of restrictor(s) to
balance the oil level in the compressor. Refer to unit
Installation, Operation, and Maintenance
manual for
proper size and location of the restrictor.
•
When brazing refrigerant connections, protect
compressor body and terminal box from torch heat
damage.
•
When brazing, always use a nitrogen purge to prevent
the formation of copper oxide contamination that can
damage the compressor.
•
The 182–361 nominal capacity compressor has an
internal check valve. When pressurizing the system, it
is important to never allow the low-side pressure to
exceed the high-side pressure by more than 5 bar
(72 psig). Such a pressure differential could result in
compressor damage. Also, slowly raise the pressure
over a two-minute time period to allow sufficient time
for the internal pressures in the compressor to
equalize.
Electrical Connections
WARNING
Hazard of Explosion and Deadly Gases!
Failure to follow all proper safe refrigerant handling
practices could result in death or serious injury.
Never solder, braze or weld on refrigerant lines or any
unit components that are above atmospheric pressure
or where refrigerant may be present. Always remove
refrigerant by following the guidelines established by
the EPA Federal Clean Air Act or other state or local
codes as appropriate. After refrigerant removal, use dry
nitrogen to bring system back to atmospheric pressure
before opening system for repairs. Mixtures of
refrigerants and air under pressure may become
combustible in the presence of an ignition source
leading to an explosion. Excessive heat from soldering,
brazing or welding with refrigerant vapors present can
form highly toxic gases and extremely corrosive acids.
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